Technical Field
The present invention relates to a treatment apparatus and a method for controlling the same.
Background Art
There is generally known a treatment apparatus for treating body tissues by use of high frequency energy or thermal energy. For example, Japanese Patent Application Laid-Open No. 2012-125338 Publication and Japanese Patent Application Laid-Open No. 2012-161566 Publication disclose therein the following treatment apparatuses. That is, the treatment apparatuses include an openable/closable holding part for gripping a body tissue to be treated. A portion of the holding member contacting with a body tissue is provided with a high frequency electrode for applying a high frequency voltage. Further, the high frequency electrode is provided with a heat generation chip as an electrothermal conversion element for heating the high frequency electrode. The holding part is provided with a cutter. In use of such a treatment apparatus, the holding part first grips a body tissue. The holding part anastomoses the body tissue by applying a high frequency voltage to the body tissue and further heating the body tissue by use of the heat generation chip. Ends of the body tissue can be removed by the cutter provided in the holding part while they are joined.
For example, Japanese Patent Application Laid-Open No. 2012-125338 Publication discloses that in temperature control of the heat generation chip for heating a body tissue, a temperature of an electric resistance pattern is acquired based on a resistance value of the electric resistance pattern as a heat generator and a temperature of the high frequency electrode functioning as a heat transfer part contacting with the body tissue is estimated based on the temperature. Further, Japanese Patent Application Laid-Open No. 2012-125338 Publication discloses that power to be supplied to the heat generation chip is subjected to feedback control based on a difference between the estimated temperature of the high frequency electrode and a target temperature thereby to heat the body tissue at the target temperature.
Further, for example, Japanese Patent Application Laid-Open No. 2012-161566 Publication discloses that a temperature difference value between a temperature of the electric resistance pattern used for the above feedback control and a temperature of the high frequency electrode functioning as a heat transfer part is acquired based on the temperature of the electric resistance pattern when different magnitudes of power are supplied to the heat generation chip.
With the techniques according to Japanese Patent Application Laid-Open No. 2012-125338 Publication and Japanese Patent Application Laid-Open No. 2012-161566 Publication, in order to keep a temperature of the heat transfer part such as high frequency electrode at the target temperature, the target temperature of the electric resistance pattern is updated based on the temperature of the heat transfer part and the supplied power each time feedback is repeated. However, such control cannot accurately process the update of the target temperature of the electric resistance pattern and the update of the supplied power for achieving the target temperature at the same time depending on a performance of a used power supply or drive circuit, which can be unstable due to oscillation.